44 research outputs found
Metabolic and physiological responses of shiraz and cabernet sauvignon (Vitis vinifera L.) to near optimal temperatures of 25 and 35 °C
No full textShiraz and Cabernet Sauvignon (Cs) grapevines were grown at near optimal temperatures (25 or 35 °C). Gas exchange, fluorescence, metabolic profiling and correlation based network analysis were used to characterize leaf physiology. When grown at 25 °C, the growth rate and photosynthesis of both cultivars were similar. At 35 °C Shiraz showed increased respiration, non-photochemical quenching and reductions of photosynthesis and growth. In contrast, Cs maintained relatively stable photosynthetic activity and growth regardless of the condition. In both cultivars, growth at 35 °C resulted in accumulations of secondary sugars (raffinose, fucose and ribulose) and reduction of primary sugars concentration (glucose, fructose and sucrose), more noticeably in Shiraz than Cs. In spite of similar patterns of metabolic changes in response to growth at 35 °C, significant differences in important leaf antioxidants and antioxidant precursors (DHA/ascorbate, quinates, cathechins) characterized the cultivar response. Correlation analysis reinforced Shiraz sensitivity to the 35 °C, showing higher number of newly formed edges at 35 °C and higher modularity in Shiraz as compared to Cs. The results suggest that the optimal growth temperatures of grapevines are cultivar dependent, and allow a first insight into the variability of the metabolic responses of grapevines under varied temperatures
Metabolite and transcript profiling of berry skin during fruit development elucidates differential regulation between Cabernet Sauvignon and Shiraz cultivars at branching points in the polyphenol pathway
No full textGrapevine berries undergo complex biochemical changes during fruit maturation, many of which are dependent upon the variety and its environment. In order to elucidate the varietal dependent developmental regulation of primary and specialized metabolism, berry skins of Cabernet Sauvignon and Shiraz were subjected to GC-MS and LC-MS based metabolite profiling from pre-veraison to harvest. The generated dataset was augmented with RNAseq-transcript profiling. The analysis of the metabolite data revealed similar developmental patterns of change in primary metabolites between the two cultivars. In contrast, quite distinct pattern of change was apparent in specialized metabolites towards maturation, suggesting a varietal-dependent metabolic regulation, Transcript profiling revealed coordinated increased transcript abundance for genes encoding enzymes of committing steps in the phenylpropanoid pathway. The anthocyanin metabolite profile showed F3'5'H-mediated delphinidin-type anthocyanin enrichment in both varieties toward maturation, consistent with the transcript data, indicating that the F3’5’H-governed branching step dominates the anthocyanin profile at late berry development. The comparative metabolite profiles and RNAseq analysis of two physiologically different dark-skinned grape varieties revealed the underlying commonalities and cultivar-specificities of berry metabolism and its regulation. Enhanced stress related metabolism, e.g. trehalose, stilbene and ABA in Shiraz berry-skin corroborate its relatively higher susceptibility to environmental cue
The transporter GAT1 plays an important role in GABA-mediated carbon-nitrogen interactions in Arabidopsis
No full textGlutamate derived γ-aminobutyric acid (GABA) is synthetized in the cytosol prior to delivery to the mitochondria where it is catabolized via the TCA cycle. GABA accumulates under various environmental conditions, but an increasing number of studies show its involvement at the crossroad between C and N metabolism. To assess the role of GABA in modulating cellular metabolism, we exposed seedlings of A. thaliana GABA transporter gat1 mutant to full nutrition medium and media deficient in C and N combined with feeding of different concentrations (0.5 and 1 mM) of exogenous GABA. GC-MS based metabolite profiling showed an expected effect of medium composition on the seedlings metabolism of mutant and wild type alike. That being said, a significant interaction between GAT1 deficiency and medium composition was determined with respect to magnitude of change in relative amino acid levels. The effect of exogenous GABA treatment on metabolism was contingent on both the medium and the genotype, leading for instance to a drop in asparagine under full nutrition and low C conditions and glucose under all tested media, but not to changes in GABA content. We additionally assessed the effect of GAT1 deficiency on the expression of glutamate metabolism related genes and genes involved in abiotic stress responses. These results suggest a role for GAT1 in GABA-mediated metabolic alterations in the context of the C-N equilibrium of plant cells
Author Correction: d-Glutamate production by stressed Escherichia coli gives a clue for the hypothetical induction mechanism of the ALS disease
No full textAn in vivo stable isotope labeling method to investigate individual matrix protein synthesis, ribosomal biogenesis, and chondrocyte proliferation in murine articular cartilage
No full text<p>These experiments have used a stable-isotope method using <em>in vivo</em> deuterium oxide labeling and mass spectrometry to measure protein concentration, protein half-life, cell proliferation, and ribosomal biogenesis in a single sample of murine articular cartilage. We hypothesized that a 60-day labeling period would capture age-related declines in cartilage matrix protein content, protein synthesis rates, and chondrocyte proliferation. Knee cartilage was isolated from 25- and 90-week-old female C57BL/6J mice treated with deuterium oxide for 15, 30, 45 and 60 days. We measured protein abundance and half-lives using high resolution accurate mass spectrometry (HRAM) and d2ome data processing software. </p>The data files are from LC-MS experiments acquired on a ThermoScientific QEx Plus mass spectrometer system. Data were analyzed using the program Skyline to determine total peak area and the isotope ratios. The format is the .raw used by the Thermo data system. There are 4 Excel file that contain the keys to the sample analyzed in each datafile
d-Glutamate production by stressed Escherichia coli gives a clue for the hypothetical induction mechanism of the ALS disease
No full textAbstract In the search for the origin of Amyotrophic Lateral Sclerosis disease (ALS), we hypothesized earlier (Monselise, 2019) that d-amino acids produced by stressed microbiome may serve as inducers of the disease development. Many examples of d-amino acid accumulation under various stress conditions were demonstrated in prokaryotic and eukaryotic cells. In this work, wild-type Escherichia coli, members of the digestive system, were subjected to carbon and nitrogen starvation stress. Using NMR and LC–MS techniques, we found for the first time that d-glutamate accumulated in the stressed bacteria but not in control cells. These results together with the existing knowledge, allow us to suggest a new insight into the pathway of ALS development: d-glutamate, produced by the stressed microbiome, induces neurobiochemical miscommunication setting on C1q of the complement system. Proving this insight may have great importance in preventive medicine of such MND modern-age diseases as ALS, Alzheimer, and Parkinson
Independent effects of dietary fat and sucrose content on chondrocyte metabolism and osteoarthritis pathology in mice
No full textObesity is one of the most significant risk factors for knee osteoarthritis. However, therapeutic strategies to prevent or treat obesity-associated osteoarthritis are limited because of uncertainty about the etiology of disease, particularly with regard to metabolic factors. High-fat-diet-induced obese mice have become a widely used model for testing hypotheses about how obesity increases the risk of osteoarthritis, but progress has been limited by variation in disease severity, with some reports concluding that dietary treatment alone is insufficient to induce osteoarthritis in mice. We hypothesized that increased sucrose content of typical low-fat control diets contributes to osteoarthritis pathology and thus alters outcomes when evaluating the effects of a high-fat diet. We tested this hypothesis in male C57BL/6J mice by comparing the effects of purified diets that independently varied sucrose or fat content from 6 to 26 weeks of age. Outcomes included osteoarthritis pathology, serum metabolites, and cartilage gene and protein changes associated with cellular metabolism and stress-response pathways. We found that the relative content of sucrose versus cornstarch in low-fat iso-caloric purified diets caused substantial differences in serum metabolites, joint pathology, and cartilage metabolic and stress-response pathways, despite no differences in body mass or body fat. We also found that higher dietary fat increased fatty acid metabolic enzymes in cartilage. The findings indicate that the choice of control diets should be carefully considered in mouse osteoarthritis studies. Our study also indicates that altered cartilage metabolism might be a contributing factor to how diet and obesity increase the risk of osteoarthritis
Parental Effects on Seed Transcriptome-Metabolome
No full textTranscriptome analyses on seeds developed in different parental condition
Effects of Leptin and Body Weight on Inflammation and Knee Osteoarthritis Phenotypes in Female Rats
No full textABSTRACT Leptin is a proinflammatory adipokine that contributes to obesity‐associated osteoarthritis (OA), especially in women. However, the extent to which leptin causes knee OA separate from the effect of increased body weight is not clear. We hypothesized that leptin is necessary to induce knee OA in obese female rats but not sufficient to induce knee OA in lean rats lacking systemic metabolic inflammation. The effect of obesity without leptin signaling was modeled by comparing female lean Zucker rats to pair fed obese Zucker rats, which possess mutant fa alleles of the leptin receptor gene. The effect of leptin without obesity was modeled in female F344BN F1 hybrid rats by systemically administering recombinant rat leptin versus saline for 23 weeks via osmotic pumps. Primary OA outcomes included cartilage histopathology and subchondral bone micro‐computed tomography. Secondary outcomes included targeted cartilage proteomics, serum inflammation, and synovial fluid inflammation following an acute intra‐articular challenge with interleukin‐1β (IL‐1β). Compared to lean Zucker rats, obese Zucker rats developed more severe tibial osteophytes and focal cartilage lesions in the medial tibial plateau, with modest changes in proximal tibial epiphysis trabecular bone structure. In contrast, exogenous leptin treatment, which increased plasma leptin sixfold without altering body weight, caused mild generalized cartilage fibrillation and reduced Safranin O staining compared to vehicle‐treated animals. Leptin also significantly increased subchondral and trabecular bone volume and bone mineral density in the proximal tibia. Cartilage metabolic and antioxidant enzyme protein levels were substantially elevated with leptin deficiency and minimally suppressed with leptin treatment. In contrast, leptin treatment induced greater changes in systemic and local inflammatory mediators compared to leptin receptor deficiency, including reduced serum IL‐6 and increased synovial fluid IL‐1β. In conclusion, rat models that separately elevate leptin or body weight develop distinct OA‐associated phenotypes, revealing how obesity increases OA pathology through both leptin‐dependent and independent pathways. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research
Diurnal rhythms in durum wheat triggered by Rhopalosiphum padi (bird cherry-oat aphid)
No full textAbstract Wheat is a staple crop and one of the most widely consumed grains globally. Wheat yields can experience significant losses due to the damaging effects of herbivore infestation. However, little is known about the effect aphids have on the natural diurnal rhythms in plants. Our time-series transcriptomics and metabolomics study reveals intriguing molecular changes occurring in plant diurnal rhythmicity upon aphid infestation. Under control conditions, 15,366 out of the 66,559 genes in the tetraploid wheat cultivar Svevo, representing approximately 25% of the transcriptome, exhibited diurnal rhythmicity. Upon aphid infestation, 5,682 genes lost their rhythmicity, while 5,203 genes began to exhibit diurnal rhythmicity. The aphid-induced rhythmic genes were enriched in GO terms associated with plant defense, such as protein phosphorylation and cellular response to ABA and were enriched with motifs of the WRKY transcription factor families. In contrast, the genes that lost rhythmicity due to aphid infestation were enriched with motifs of the TCP and ERF transcription factor families. While the core circadian clock genes maintain their rhythmicity during infestation, we observed that approximately 60% of rhythmic genes experience disruptions in their rhythms during aphid infestation. These changes can influence both the plant’s growth and development processes as well as defense responses. Furthermore, analysis of rhythmic metabolite composition revealed that several monoterpenoids gained rhythmic activity under infestation, while saccharides retained their rhythmic patterns. Our findings highlight the ability of insect infestation to disrupt the natural diurnal cycles in plants, expanding our knowledge of the complex interactions between plants and insects
